Construction for multi-layered vacuum super insulated cryogenic tank

ABSTRACT

A construction for a multi-layered vacuum super insulated cryogenic tank and a method for making the same is disclosed. The cryogenic tank uses an inner tank that is wrapped with multiple layers of radiation shielding and is suspended within a frame by one or more suspension members. The frame is enclosed within a fluid tight outer tank that fits snuggly against the frame. An ultra-high vacuum is created between the inner and outer tanks.

FIELD OF THE INVENTION

The present invention relates to storage tanks, and more specifically,to cryogenic storage tanks.

BACKGROUND OF THE INVENTION

Typical multi-layered vacuum super insulated cryogenic tanks utilize apair of cylindrical inner and outer tanks that are arrangedconcentrically with the inner tank residing in an interior of the outertank. There are multiple radiant heat shields, approximately 30–80,coiled around the inner tank between the inner and outer tanks. A highvacuum exists between the inner and outer tanks to further prevent heattransfer. This type of thermal insulation is called a multi-layeredvacuum super insulation. These storage tanks are capable of storingfluids at cryogenic temperatures.

The inner tank is positioned within the outer tank so that the innertank does not contact the outer tank and so that thermal conductionpaths between the inner and outer tanks are minimized. To facilitatethis positioning, the inner tank typically has a pair of closed endpipes welded on opposite ends of the inner tank that form closed endchannels that extend into the interior of the inner tank. A pair of rodsare positioned in the channels to support the inner tank within theouter tank. The rods are designed so that the only contact between therods and the inner tank is the interface between the ends of the rodsand the ends of the channels. Opposite ends of the rods are attached tothe internal surface of the outer tank. The rods, positioned on oppositeends of the inner tank, thereby support the inner tank within the outertank.

To minimize the conductive heat paths, the rods are made from a carbonor glass fiber or other composite material. The carbon and glass fibersprovide low thermal conductivity and help to isolate the inner tank fromthe outer tank. To further reduce the possibility of heat conductionbetween the inner and outer tanks, the rods can be made longer. That is,the length that the channels extend into the interior cavity of theinner tank can be increased, which decreases the volume of the innertank, to allow for longer rods to be employed without increasing thedimensions of the outer tank. However, as the rods get longer, thebending force on the rods increases and a larger diameter rod isrequired to support the load over the longer distance. This in turnrequires a larger surface area for the contact between the rods and theinner tank which increases the amount of heat being conducted throughthe rods, thus there is a trade-off between the conduction caused by thelength of the rod and the conduction caused by the increased surfacearea of the rods in contact with the ends of the channel to support theloading caused by the extended length. Accordingly, it would beadvantageous to provide an apparatus for supporting the inner tankwithin the outer tank that has a minimal intrusion on the inner tankwhile also limiting the conductive heat paths between the inner andouter tanks.

With the advent of fuel cell technology and the inclusion of fuel cellson mobile platforms (i.e. vehicles), there is a need for an onboardhydrogen storage system. The space in which to provide for hydrogenstorage on the mobile platforms is limited. Additionally, the availablespace may be irregular in shape. The typical cryogenic storage tanks, asdiscussed above, are cylindrical. The cylindrical shape is used becauseit provides for cancellations of the forces applied to/on the storagetank. However, the use of a cylindrical cryogenic tank on a mobileplatform may not provide the most efficient use of the available spaceon the mobile platform. Accordingly, it would be advantageous to providea cryogenic storage tank that is non-cylindrical in shape. Furthermore,it would be advantageous to provide a cryogenic storage tank that iscapable of more closely conforming to the available space on the mobileplatform to maximize the amount of fluid that can be stored in thecryogenic tank on the mobile platform within the available space.

SUMMARY OF THE INVENTION

The present invention provides a new construction for a multi-layeredvacuum super insulated cryogenic tank. The construction suspends aninner tank inside an outer tank without the use of rods that intrudeinto the interior cavity of the inner tank. The construction allows forboth cylindrical and non-cylindrical shapes for the inner and outertanks.

A cryogenic storage tank according to the principles of the presentinvention includes a fluid tight inner tank operable to store a fluid.There is a frame surrounding the inner tank and the frame is spacedapart from the inner tank. A fluid tight outer tank surrounds the frame.A vacuum exists between the inner and outer tanks.

A method of manufacturing a cryogenic storage tank having an inner tank,a frame and an outer tank according to the principles of the presentinvention is disclosed. The method includes: (1) suspending the innertank inside the frame; (2) positioning the frame inside the outer tank;and (3) producing a vacuum between the inner and outer tanks.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a simplified exploded view of a multi-layered vacuum superinsulated cryogenic tank according to the principles of the presentinvention; and

FIG. 2 is a cross-sectional view of a multi-layered vacuum superinsulated cryogenic tank according to the principles of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following description of the preferred embodiment is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

FIGS. 1 and 2 show a preferred embodiment of a multi-layered vacuumsuper insulated cryogenic tank 20 according to the principles of thepresent invention. Cryogenic tank 20 includes an inner tank 22 which issurrounded by one or more layers of insulation 24 (shown in FIG. 2 only)and suspended within a frame 26 such that inner tank 22 is spaced apartfrom and not in direct contact with frame 26. An outer tank 28 encasesframe 26 along with insulation 24 and inner tank 22. There is a vacuumbetween inner tank 22 and outer tank 28. The vacuum is about 10⁻⁴ mbarwhich is also referred to as an ultra-high vacuum. The insulation 24 inconjunction with the ultra-high vacuum provides a multi-layer vacuumsuper insulation or MLVSI between inner and outer tanks 22 and 28.

Other components (not shown) include conduits for filling and emptyinginner tank 22 as well as electrical leads for sensors. These othercomponents are welded to inner tank 22 and outer tank 28 to providefluid tight seals so that the ultra-high vacuum can be created betweeninner and outer tanks 22 and 28. These other components are similar toand attached in a similar manner to inner and outer tanks 22 and 28 asis conventionally known.

The construction of cryogenic tank 20 enables cryogenic tank 20 to takea non-cylindrical form. That is, cryogenic tank 20 (inner tank 22, frame26 and/or outer tank 28), unlike prior art tanks, does not need to becylindrical in shape to provide storage of fluids at cryogenictemperatures and to use a multi-layered vacuum super insulation toprovide such low temperature storage. In addition to beingnon-cylindrical, cryogenic tank 20 can also be asymmetrical. With thisability, cryogenic tank 20 can be shaped and configured to correspond toan available space in which cryogenic tank 20 is to be located. Theflexibility in the configuration allows for cryogenic tank 20 to beshaped to maximize the volume of fluid stored in cryogenic tank 20within the space available. Further, inner tank 22, frame 26 and outertank 28 may have similar or different shapes since all that is requiredis that inner tank 22 be nested in frame 26 and frame 26 be nested inouter tank 28. Insulation 24 is arranged to conform to the nestedconfiguration.

Inner tank 22 can be provided in a variety of shapes, includingnon-cylindrical shapes, such as that shown in FIGS. 1 and 2. In theconfiguration illustrated, inner tank 22 has relatively flat oppositetop and bottom surfaces 32 and 34 that are spaced apart by curved sidewall 36. The joining of top and bottom surfaces 32 and 34 to side wall36 produces a plurality of corners or corner portions 38. Inner tank 22can also have a number of projections or attachment fixtures tofacilitate suspending inner tank 22 within frame 26, as described below.Inner tank 22 is designed to store a fluid at cryogenic temperatures ofless than 100° K. Preferably, inner tank 22 is capable of storing fluidsat less than 30° K. Inner tank 22 stores the fluid at a pressure in therange of about 1 to 12 bars. Preferably, inner tank 22 stores the fluidat about 4 bars. Inner tank 22 can be used to store a variety of fluids.In a mobile application employing a fuel cell system, the fluid storedwill be hydrogen.

To meet these functional requirements, inner tank 22 can be made from avariety of materials that are capable of withstanding the cryogenictemperatures experienced and the pressure differentials between theinterior of inner tank 22 and the ultra-high vacuum between inner tank22 and outer tank 28. Preferably, inner tank 22 is made from a metal,such as stainless steel, aluminum or an alloy of aluminum. The use ofmetal facilitates the sealing of the other components to inner tank 22.For example, the other components can be sealed to inner tank 22 bywelding.

Inner tank 22, as stated above, is suspended within frame 26 such thatinner tank 22 is not in direct contact with frame 26. To suspend innertank 22 within frame 26, a plurality of suspension members 50 are usedto support inner tank 22 within frame 26 without inner tank 22 being indirect contact with frame 26. Suspension members 50 can be attached toinner tank 22 in a variety of ways. For example, inner tank 22 can havea variety of projections, eyelets, or similar attachment fixtures towhich suspension members 50 can be secured.

Suspension members 50 have opposite first and second ends 52 and 54.First end 52 of each suspension member 50 is secured to inner tank 22while second end 54 of each suspension member 50 is secured to frame 26,as described below. The first ends 52 are attached to inner tank 22along top and bottom surfaces 32 and 34, as shown in FIG. 1. Thespecific locations of the attachments of first ends 52 of suspensionmembers 50 can vary depending upon the desired manner in which innertank 22 is to be suspended within frame 26. For example, suspensionmembers 50 can be spaced along top and bottom surfaces 32 and 34adjacent side walls 36 to provide a generally uniform suspension of topand bottom surfaces 32 and 34 of inner tank 22 within frame 26. As canbe seen, a suspension member 50 is located in each corner portion 38 ofinner tank 22. It should be appreciated, however, that otherarrangements and connection points of suspension members 50 to innertank 22 can be employed without departing from the scope of the presentinvention.

Suspension members 50 are under tensile loading only and are preferablyflexible to allow suspension members 50 to be attached to inner tank 22and/or frame 26 at any of a variety of locations. Suspension members 50are preferably filaments that have low thermal conductivity. Thefilaments can be either monofilaments or multifilaments. To provide forthe low thermal conductivity, suspension members 50 are preferably madefrom a carbon fiber or glass fiber. However, other materials having lowconductivity that are flexible can be employed without departing fromthe scope of the present invention. Suspension members 50 suspend innertank 22 within frame 26 under tensile loading only and no compressive,shear or bending loading of suspension members 50 occurs. With thesuspension members 50 being only under tensile loading, the length ofsuspension members 50 can be increased, to provide less heat conductionbetween inner tank 22 and frame 26, without increasing the crosssectional area of suspension members 50. In other words, if it isdesired to double the length of suspension members 50 to provide afurther distance between inner tank 22 and frame 26, the cross sectionalarea of suspension members 50 does not need to be increased and resultsin approximately a one-half reduction in the conduction of heat throughsuspension members 50.

The use of suspension members 50 on both the top and bottom surfaces 32and 34 of inner tank 22 limit the movement or bouncing of inner tank 22within cryogenic tank 20 due to movement or bouncing of the mobileplatform on which cryogenic tank 20 is utilized. Suspension members 50are designed to have a natural frequency that dampens inner tank 22within cryogenic tank 20 to limit and/or prevent oscillations of innertank 22.

Suspension members 50 are shown as being a plurality of suspensionmembers 50 that suspend inner tank 22 within frame 26, however, itshould be appreciated that a single suspension member 50 could beemployed on each of the top and bottom surfaces 32 and 34. For example,a single suspension member 50 can be connected to a central location ontop surface 32 of inner tank 22 and to a single location on frame 26 anda single suspension member 50 can be connected to a central location onbottom surface 34 of inner tank 22 and to a single location on frame 26to suspend inner tank 22 within frame 26. Accordingly, the exact numberof suspension members 50 used to suspend inner tank 22 within frame 26can vary and will depend upon the desired design and functionality ofcryogenic tank 20.

Insulation 24 in conjunction with the ultra-high vacuum provides amulti-layered vacuum super insulation, as is known in the art.Insulation 24 consists of a large number, approximately 30–80, ofreflective foil thermal radiation shields, preferably made of aluminum,which are coiled or wrapped around inner tank 22. That is, because theprimary cause of heat gain in inner tank 22 is due to thermal radiation,insulation 24 provides multiple layers of thermal radiation shielding toinhibit the influx of heat via radiation into inner tank 22. Theinsulation layers 24 can be provided as a single piece of insulationthat is wrapped around inner tank 22, the other components, andsuspension members 50. Alternatively, insulation layers 24 can be aplurality of individual sheets that are each wrapped around inner tank22. The insulation layers 24 are wrapped around inner tank 22 untilapproximately 30–80 layers of insulation is obtained. This applicationtechnique is similar to that which is currently done and is thereforenot discussed in further detail.

Frame 26, as shown in FIG. 1, consists of rigid top and bottom portions60 and 62 that are attached together during the assembling of cryogenictank 20. Top and bottom portions 60 and 62 can be attached together by avariety of means. For example, top and bottom portions 60 and 62 can beattached together by welding or mechanical fasteners. Top and bottomportions 60 and 62 are shaped to be complementary to inner tank 22 andto conform to the desired external configuration of cryogenic tank 20.Top and bottom portions 60 and 62 are dimensioned to allow sufficientspace for insulation layers 24 and for the suspension of inner tank 22within frame 26 without inner tank 22 being in direct contact with frame26.

Both top and bottom portions 60 and 62 have a plurality of openings 64that serve a variety of purposes. Openings 64 function to reduce theweight of frame 26 so that cryogenic tank 20 can be of a minimal weightwhile still meeting the operational performance requirements ofcryogenic tank 20. Openings 64 also facilitate the assembly of cryogenictank 20 by allowing access to inner tank 22, as described below.Furthermore, openings 64 allow the other components that are connectedto inner tank 22 to pass through frame 26. The specific configuration offrame 26 and the locations, sizes and shapes of openings 64 are based onan intelligent design of frame 26 to provide the required support forcryogenic tank 20 while minimizing the weight of cryogenic tank 20. Inthe preferred embodiment, as shown, frame 26 is a triangulated framethat disburses loading on frame 26 throughout various portions to avoidconcentration of forces in small areas.

Frame 26 functions to suspend inner tank 22 within frame 26.Accordingly, frame 26 and, more specifically, the attachment points forsuspension members 50 to frame 26 are designed to provide the requiredsupport to suspend inner tank 22 within frame 26. As stated above,second ends 54 of suspension members 50 are attached to frame 26 tosuspend inner tank 22 within frame 26. Suspension members 50 can beattached to frame 26 in a variety of manners. For example, projectionsor eyelets can be provided on frame 26 to secure second ends 54 ofsuspension members 50 to frame 26. Alternatively, second ends 54 ofsuspension members 50 can be passed through one or more openings 64 andtied to frame 26. Additionally, the location(s) on frame 26 wheresuspension members 50 are attached can also vary. Thus, suspensionmembers 50 can be secured to frame 26 in a variety of ways and at avariety of locations.

In addition to suspending inner tank 22 within frame 26, frame 26 alsoserves to support outer tank 28 against the pressure differentialbetween the ultra-high vacuum between inner and outer tanks 22 and 28and the pressure external to cryogenic tank 20. In other words, outertank 28 is pulled or sucked toward inner tank 22 as a result of thepressure differential between the ultra-high vacuum and the pressure ofthe environment within which cryogenic tank 20 is employed and frame 26supports outer tank 28. Thus, frame 26 supports outer tank 28 and outertank 28 acts as a skin over frame 26 that provides a fluid tightenvironment encasing frame 26 and inner tank 22. Because of thevariations in the shapes of inner tank 22, the desired overall shape ofcryogenic tank 20, and the variety of locations at which suspensionmembers 50 can be used to suspend inner tank 22 from frame 26, frame 26can take a variety of shapes, forms, and configurations based on theappropriate intelligent design of frame 26 to serve its intended purposeof suspending inner tank 22 and supporting outer tank 28.

To meet these functional requirements, frame 26 can be made from avariety of materials. For example, frame 26 can be made from metal suchas stainless steel, aluminum or an alloy of aluminum. Preferably, frame26 is made from the same material as inner tank 22 and outer tank 28.However, it should be appreciated that frame 26, can be made from othermaterials that have the appropriate temperature and strengthcharacteristics to provide the functionality of frame 26 describedabove. Additionally, while frame 26 is shown as being comprised of topand bottom portions 60 and 64, frame 26 can be provided in any number ofportions or pieces without departing from the scope of the presentinvention, however, not all of the benefits of the present invention maybe realized.

Outer tank 28 has top and bottom portions 70 and 72 that are attachedtogether during the assembly of cryogenic tank 20. Top and bottomportions 70 and 72 can be attached together in a variety of manners thatprovide a fluid tight outer tank 28 that is capable of sustaining avacuum between inner and outer tanks 22 and 28. Preferably, top andbottom portions 70 and 72 are attached together by welding. Outer tank28, like frame 26, can come in a variety of shapes depending upon thedesired external configuration of cryogenic tank 20. Top and bottomportions 70 and 72 are configured to be complementary to the respectivetop and bottom portions 60 and 62 of frame 26 so that outer tank 28 iscomplementary to frame 26. Preferably, outer tank 28 is configured tofit snuggly or tightly against frame 26 with outer tank 28 in directcontact with frame 26. The use of frame 26 to support outer tank 28enables outer tank 28 to be dimensioned (thickness) to allow outer tank28 to deform inwardly against frame 26 as a result of the pressuredifferential between the ultra-high vacuum between inner and outer tanks22 and 28 and the pressure of the environment within which cryogenictank 20 is located. With the outer tank 28 deforming as a result of thepressure differential, frame 26 serves to support outer tank 28 againstthe force of the pressure differential, as discussed above. While outertank 28 is shown as being comprised of top and bottom portions 70 and72, outer tank 28 can be provided in any number of portions or piecewithout departing from the scope of the present invention.

Outer tank 28 can be made from a variety of materials. Preferably, outertank 28 is metallic and made from the same material as inner tank 22.Specifically, outer tank 28 is preferably made from stainless steel,aluminum, or an alloy of aluminum. By making outer tank 28 and innertank 22 of the same material, the welding of the other components toinner and outer tanks 22 and 28 is simplified.

The construction of cryogenic tank 20 improves the assembly of cryogenictank 20 over that of typical cryogenic tanks. To assemble cryogenic tank20, inner tank 22 is first constructed. The other components are thenwelded to inner tank 22 to provide a fluid tight seal between the othercomponents and the interior of inner tank 22. One or more suspensionmembers 50 are then attached to inner tank 22 at the desired attachmentlocations as dictated by the design of cryogenic tank 20. With the othercomponents and suspension members 50 attached to inner tank 22,insulation layers 24 can then be applied to inner tank 22. Specifically,the insulation layers are wrapped around inner tank 22, as is known inthe art. One of the portions of frame 26 can then be positioned on oradjacent inner tank 22 with the other components welded to inner tank 22passing through one or more openings 64. The second ends 54 ofsuspension members 50 are then attached to the appropriate attachmentlocations on the portion of frame 26. Openings 64 in frame 26 facilitatethis assembly by allowing a worker or machine assembling cryogenic tank20 to reach through one or more of the openings 64 to grab suspensionmembers 50 and secure suspension members 50 to frame 26. As statedabove, second end 54 of suspension members 50 can be passed through oneor more openings 64 and tied to frame 26 or secured to an attachmentfixture. The portion of frame 26 to which inner tank 22 is now connectedcan then be elevated to suspend inner tank 22 from that portion of frame26. The other portion(s) of frame 26 can then be mated to the portion offrame 26 already connected to inner tank 22 by suspension members 50.The top and bottom portions 60 and 62 of frame 26 can then be securedtogether by welding or other means as discussed above. With frame 26secured, the opposite side of inner tank 22 can then be secured to theother portion(s) of frame 26 via suspension members 50 located on theopposite side of inner tank 22. Thus, inner tank 22 is now completelysuspended within frame 26 by suspension members 50.

With top and bottom portions 60 and 62 of frame 26 secured to oneanother and inner tank 22 suspended within frame 26, frame 26 is thenplaced in either top or bottom portion 70 and 72 of outer tank 28. Theother portion of outer tank 28 is then positioned over frame 26. Whenpositioning top and bottom portions 70 and 72 of outer tank 28 on frame26, the other components extending from inner tank 22 pass throughcomplementary opening(s) (not shown) in outer tank 28. The two portionsof outer tank 28 are then connected together by welding and the othercomponents sealed to outer tank 28 by welding. The welding of top andbottom portions 70 and 72 of outer tank 28 and of the other componentsto outer tank 28 provides a fluid tight outer tank 28 that is capable ofsustaining a vacuum between inner tank 22 and outer tank 28. With thecryogenic tank 20 now assembled, an ultra-high vacuum can then becreated between inner and outer tanks 22 and 28, via a variety ofmethods known in the art. The creation of the ultra-high vacuum betweeninner and outer tanks 22 and 28 may cause outer tank 28 to deforminwardly toward frame 26 wherein outer tank 28 is supported by frame 26against the pressure differential between the ultra-high vacuum and thepressure external of cryogenic tank 20. With the assembly of cryogenictank 20 now complete, cryogenic tank 20 can be employed in a desiredapplication.

Thus, a cryogenic tank 20 according to the principles of the presentinvention provides for easier assembly and a better utilization of spaceby being capable of providing cryogenic storage of a fluid in anon-cylindrical configuration. Additionally, cryogenic tank 20 can be ofa lower cost due to the ease of manufacturing and have a reduced weightdue to the intelligent design of frame 26 and the use of weight savingopenings 64. The description of the invention is merely exemplary innature and, thus, variations that do not depart from the gist of theinvention are intended to be within the scope of the invention. Suchvariations are not to be regarded as a departure from the spirit andscope of the invention.

1. A cryogenic storage tank comprising: a fluid tight inner tankoperable to store a fluid; a frame extending around all sides of saidinner tank, said frame being spaced apart from said inner tank; a fluidtight outer tank surrounding said frame; and a vacuum between said innerand outer tanks.
 2. The storage tank of claim 1, further comprising atleast one flexible suspension member, said suspension member beingconnected to said inner tank and connected to said frame, and saidsuspension member suspending said inner tank within said frame.
 3. Thestorage tank of claim 2, wherein said at least one suspension member isunder tensile force when suspending said inner tank within said frame.4. The storage tank of claim 2, wherein said at least one suspensionmember is a filament.
 5. The storage tank of claim 2, wherein said atleast one suspension member is made from at least one of carbon fiberand glass fiber.
 6. The storage tank of claim 2, wherein said at leastone suspension member is a plurality of suspension members and saidsuspension members are attached to corners of said inner tank.
 7. Thestorage tank of claim 1, wherein said frame includes at least twomembers that are connected together to form said frame and to surroundsaid inner tank.
 8. The storage tank of claim 7, wherein said at leasttwo members are welded together.
 9. The storage tank of claim 1, whereinsaid outer tank includes at least two members that are connectedtogether to form said outer tank and to surround said frame.
 10. Thestorage tank of claim 9, wherein said at least two members are weldedtogether.
 11. The storage tank of claim 1, wherein said frame has aplurality of openings.
 12. The storage tank of claim 11, wherein saidinner tank and said frame are arranged to provide access to said innertank through at least one of said openings.
 13. The storage tank ofclaim 1, wherein said inner tank, said frame and said outer tank arenon-cylindrical in shape.
 14. The storage tank of claim 1, furthercomprising at least one layer of insulation between said inner tank andsaid frame.
 15. The storage tank of claim 1, wherein said frame is indirect contact with said outer tank.
 16. The storage tank of claim 1,wherein said frame is shaped to be complementary to a shape of anentirety of said inner tank.
 17. The storage tank of claim 1, whereinsaid frame supports said outer tank against said vacuum between saidinner and outer tanks.
 18. The storage tank of claim 1, wherein saidouter tank is contoured to be complementary to said frame so that saidouter tank fits tightly against said frame.
 19. The storage tank ofclaim 1, wherein said inner and outer tanks are made from at least oneof stainless steel, aluminum and an alloy of aluminum.
 20. The storagetank of claim 1, wherein said inner tank is operable to store a fluid atless than about 30° K.
 21. The storage tank of claim 1, wherein saidframe is nested in said outer tank.
 22. The storage tank of claim 1,wherein said outer tank is free of attachment to said inner tank.
 23. Acryogenic storage tank comprising: a fluid tight inner tank operable tostore a fluid; a frame surrounding at least a portion of said innertank, said frame being spaced apart from said inner tank; a fluid tightouter tank disposed outside of said frame; and a vacuum between saidinner and outer tanks, wherein said outer tank is deformed against saidframe by said vacuum between said inner and outer tanks.
 24. A cryogenicstorage tank comprising: an inner tank operable to store a fluid; aframe surrounding an entirety of said inner tank; at least one flexiblesuspension member connected to said inner tank and connected to saidframe, said at least one suspension member suspending said inner tankinside said frame; an outer tank surrounding said frame; a vacuumbetween said inner and outer tank; and wherein at least one of saidinner tank, frame, and outer tank is non-cylindrical.
 25. The storagetank of claim 24, wherein said at least one suspension member is afilament.
 26. The storage tank of claim 24, wherein said at least onesuspension member is made from at least one of carbon fiber and glassfiber.
 27. The storage tank of claim 24, wherein said frame has aplurality of openings.
 28. The storage tank of claim 24, wherein saidinner tank is operable to store a fluid at less than about 30°K.
 29. Thestorage tank of claim 24, wherein said outer tank is deformed againstsaid frame by said vacuum.
 30. The storage tank of claim 24, whereinsaid frame is spaced apart from said inner tank.
 31. A cryogenic storagetank comprising: a fluid tight inner tank operable to store a fluid; aframe surrounding at least a portion of said inner tank, said framebeing spaced apart from said inner tank; a plurality of suspensionmembers suspending said inner tank from and within said frame; a fluidtight outer tank disposed outside of said frame; and a vacuum betweensaid inner and outer tanks, wherein a suspension force imparted on saidframe by said suspension members is borne entirely by said frame.
 32. Acryogenic storage tank comprising: a fluid tight inner tank operable tostore a fluid; a frame surrounding at least a portion of said innertank, said frame being spaced apart from said inner tank; a fluid tightouter tank disposed outside of said frame; at least one flexiblesuspension member, said suspension member being connected to said innertank and connected to said frame, and said suspension member suspendingsaid inner tank within said frame; and a vacuum between said inner andouter tanks, wherein said inner tank has relatively flat opposite topand bottom surfaces and said at least one suspension member is aplurality of suspension members spaced about said top and bottomsurfaces of said inner tank.